package iterator;

/**
 * @author wcj
 * @Date 2021/7/4 20:26
 * @Version 1.0
 */
public abstract class Iterator {

    /**
     * first
     *
     * @return
     */
    public abstract Object first();

    /**
     * next
     *
     * @return
     */
    public abstract Object next();

    /**
     * hasNext
     *
     * @return
     */
    public abstract boolean hasNext();

    /**
     * current
     *
     * @param index
     * @return
     */
    public abstract Object current(int index);
}
